east coast gas and the santos gsa

Given all the current press and focus around the issue of looming East Coast Gas "crisis"/price rises, does anyone have a good understanding of what the revised GSA could/is likely to deliver NXS in terms of better cashflow and in what timeframes?

As best I can understand from the annual report, the upside is very contingent on what they might find by drilling Longtom-5 and additional work to Longtom-4 etc., but I have no idea what that might actually/reasonably translate into $$$ if the gas is there.

For those who understand the business better than me ( which wouldn't be hard) are these things estimateable at this stage ? and shouldn't the company being trying to be more explicit and trying to quantify and communicate the dollar value of the upside from Longtom in the current East Coast Gas market scenario ?